I know back when my pdoc was experimenting with different meds he put me on thorozine before I had my neck fusion surgery. On top of that my neuroligist had me on compozine for my nausea from the continual migraine pain I had.
After I had recovered from the surgery meds stayed the same. Then this horrible experience happened. I couldn't coordinate my hands to feed myself & I couldn't walk without assistance (not a result from the neck fusion) I went to urgent care thinking it was the beginnings of Parkinson's. Turned out they realized it was a reaction to the thorozine. I stopped taking that med & a month later still no improvement. Went back to the neurologist & he realizer thst the compozine was still causing the reaction...& stopped that med. He said that sometimes the reaction doesn't go away after being that bad. It took over a month longer but the reaction went away totally. Maybe permanent reactions even after going off a med is what they are referring to?